Objectives: The Quick Environment Exposure Sensitivity Inventory (QEESI(c)) has been used as a questionnaire to evaluate subjective symptoms of patients with multiple chemical sensitivity (MCS), also known as idiopathic environmental intolerance, in Japan. However, no cutoff value for Japanese subjects has yet been established. We designed this study to establish a cutoff value for Japanese subjects using QEESI(c) for screening of MCS patients.
Methods: A questionnaire using the QEESI(c) was administered to 103 MCS patients and 309 healthy control subjects matched for age and sex. QEESI(c) scores of the two groups were compared using logistic regression analysis, receiver operating characteristic analysis, and the Mann-Whitney test.
Results: Cutoff values for Japanese subjects were determined for the Chemical Intolerance subscale (40), Symptom Severity subscale (20), and Life Impact subscale (10). The subjects whose scores exceeded the cutoff values in any two subscales accounted for 88.4% of the patients but only 14.5% of the controls.
Conclusions: Our results suggest that subjects meeting two out of three subscale criteria can be screened as "patients suffering from a low level of environmental chemicals such as MCS" in Japan.